多壁碳纳米管/聚乳酸复合超细纤维的制备及性能

通过静电纺丝法制备出多壁碳纳米管（MWNTs）增强聚乳酸（PLA）复合超细纤维膜。用扫描电镜、透射电镜、差示扫描量热仪、热重分析仪对MWNTs/PLA复合超细纤维进行了表征,并进行了拉伸测试。结果表明,MWNTs分散于PLA纤维中,随着MWNTs含量的增加,纤维平均直径先减小后增大,MWNTs的加入会降低PLA的结晶度...     

MWNTs与GNPs—CHIT修饰的过氧化氢生物传感器

在玻碳电极（GCE）上自组装一层多壁碳纳米管（MWNTs）,构建负电荷的界面,然后,静电吸附一层阳离子电子媒介体硫堇（Thi）,再由共价键作用自组装一层纳米金（GNPs）,壳聚糖（CHIT）混合溶液的复合薄膜,通过静电吸附辣根过氧化物酶（HRP）制得过氧化氢（H2O2）生物传感器。采用循环伏安法和计时电流法考察了该生物传感器的电化学性质,并研究了该修饰电极对H2O2的催化还原作用。生物传感器的响应电流与H2O2浓度在8．2×10^-6～1．1×10^-3mol／L范围内呈现线性关系,检出限为5．8×10^-7mol／L,达到95％稳态响应时间约为15s。将此生物传感器用于H2O2的检测,结果令人满意。     

A simple approach towards sulfonated multi-walled carbon nanotubes supported by Pd catalysts for methanol electro-oxidation

Functionalized benzenesulfonic groups were grafted onto the surface of multi-walled carbon nanotubes (MWCNTs) supported Pd catalysts in direct methanol fuel cells by a new and simple in situ radical polymerization of 4-styrenesulfonate and isoamyl nitrite. The resultant sulfonated MWCNTs-supported Pd catalysts (S-MWCNTs/Pd) were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectrometry measurements. Electrochemical characterizations of S-MWCNTs/Pd catalysts for methanol electro-oxidation in alkaline solution were investigated by cyclic voltammetry techniques. These results showed that S-MWCNTs/Pd exhibited higher electrocatalytic activity, enhanced CO tolerance and better stable life than did that with the unsulfonated counterparts, mainly due to the easier access with methanol and well dispersed distribution of the S-MWCNTs/Pd catalysts in water. In addition, compared with traditional sulfonation of MWCNTs, this new approach is more advantageous to make small and uniform dispersion of Pd particles loaded onto the surfaces of sulfonated MWCNTs, indicating it is a simple, rapid, and efficient method to functionalize MWCNTs.     

Mechanical properties of hard Cr-MWNT composite coatings

Chromium-multiwalled carbon nanotubes (Cr-MWNT) composite coatings are electrodeposited from “environmentally acceptable” trivalent Cr electrolytes containing MWNTs under ultrasonic agitation. The structures, hardness and tribological behaviors are investigated using the transmission electron microscope (TEM), field-emission scanning electron microscope (FE-SEM), Vickers hardness indenter, tribology tester and three-dimensional profile tester, respectively. Results show that MWNTs are dispersed evenly in Cr matrix. The introduction of MWNTs obviously improved the hardness, toughness and tribological performance of Cr coatings.     

无溶剂MWNTs纳米流体/聚丙烯纳米复合材料性能研究

以MWNTs为核,采用3-硅羟基-1-丙基氯化铵和磺酸盐PEGS,通过离子键,制备离子型无溶剂MWNTs纳米流体。通过TEM、DSC、TGA、流变仪对无溶剂MWNTs纳米流体的结构和性能进行表征。采用溶液法和机械法制备无溶剂MWNTs纳米流体/聚丙烯纳米复合材料,研究无溶剂MWNTs对聚丙烯结晶性的影响。研究表明,无溶剂纳米流体中MWNTs的含量为23.67wt%,具有固-液转变现象。无溶剂MWNTs纳米流体加入聚丙烯中,均促进了聚丙烯树脂形成晶核的过程,使形成的晶核数目增加,结晶度提高。     

大气压介质阻挡放电对多壁碳纳米管表面改性及其气敏特性

H2S是气体绝缘组合电器(gas insulated switchgear,GIS)内部一些潜伏性绝缘缺陷产生放电的重要的特征组分气体之一,检测它对设备运行状态的诊断和评估有着重要的意义。为此,采用大气压介质阻挡放电(dielectric barrier discharge,DBD)等离子体对多壁碳纳米管(multi-walled carbon nanotubes,MWNTs)进行了表面改性。实验研究了改性前后MWNTs对体积分数为50×10-6的H2S标气的气敏特性的影响以及不同改性时间对其气敏特性的影响,结果表明,改性后的MWNTs对H2S在灵敏度和响应时间方面都有较大幅度的改善;改性时间为60s的MWNTs的气敏特性要优于其它时间。对处理前后的MWNTs进行了扫描电子显微镜(SEM)和傅里叶红外光谱(FTIR)分析,结果显示,经DBD等离子体处理后的MWNTs表面变粗糙,缺陷增加,其表面引入了羟基、羧酸根和C-O等含氧基团。     

静电纺MWNTs/丝素复合纳米纤维毡的结构与性能

静电纺丝素纤维毡在水中极不稳定,力学性能较差,这些缺陷限制了其应用。将经过酸处理的多壁碳纳米管（MWNTs）均匀地分散在丝素膜甲酸溶液中,以MWNTs增强静电纺丝素纳米纤维,XPS的测定结果显示,碳纳米管并不是仅仅以物理形式混杂在丝素纤维中,而是形成了某些有助于提高增强效果的化学键。随碳纳米管质量分数的增加,纤维直径明显下降,纤维内部结构的规整性有所提高。当纺丝液中MWNTs的质量分数小于1%时,复合纤维毡的断裂强度和初始模量都有明显的增强,但是MWNTs的质量分数太大时,力学性能反而恶化。     

The effect of functionalized group concentration on the stability and thermal conductivity of carbon nanotube fluid as heat transfer media

In this research, the pristine CNTs sample synthesized by the CCVD method contains catalytic particles and the carbonaceous impurities, and then the special purification procedure was done. By different methods CNT functionalized with various concentration of COOH was prepared. The carboxylated CNTs were analyzed by back titration method for determining the COOH concentrations on the surface of the oxidized CNTs. Thermal conductivity of difference carbon nanotube fluid has been measured under the stable condition by KD₂ prob. For the first time, we have compared the effect of difference COOH concentration as important parameter in stability and heat transfer behavior of nanofluid. The results show that increasing the functionalized group causes better stability and higher thermal conductivity if the surface of MWNT does not damage in functionalize process.     

不同激发波长下多壁碳纳米管光致发光特性

用化学气相沉积法(CVD)制备了多壁碳纳米管(MWNTs),并用扫描电镜(SEM)测量了纳米管的形貌。在室温条件下,测量了样品的拉曼光谱和吸收光谱:拉曼光谱表明样品含有较多缺陷,吸收光谱说明了该样品有光致发光的通道。测量了在不同波长光的激发下样品的光致发光光谱:当用550 nm的光激发多壁碳纳米管时,观察到峰值强度弱、峰值波长约为820 nm的带状光谱;当激发波长增加到580 nm时,发射光谱变为峰值波长约为868 nm、峰值强度较强、形状相似的光谱;当激发光波长增加到600 nm时,观察到峰值强度强、峰值波长约为900 nm的带状光谱。     

MWNTs-OH/PET纳米复合材料的燃烧性能与阻燃机理研究

用原位聚合方法制备了纯PET和MWNTs-OH/PET纳米复合材料,用锥形量热仪测试了4种样品的燃烧性能,用场发射扫描电镜表征了纳米复合材料的微观机构。对比分析了4种样品的燃烧性能、烟及毒气释放量。结果表明复合材料的热释放速率(HRR)峰值及平均值,总放热量(THR)和有效燃烧热(EHC)平均值都有所降低,纳米复合材料的CO生成速率峰值较平缓且低于纯PET的CO生成速率,没有增加PET材料的毒性。从扫描电镜图和锥形量热仪测试结果可以初步断定,MWNTs-OH/PET纳米复合材料属于气相阻燃和凝固相阻燃机理。